TWI469022B - Capacitive touchscreen system and method for detecting touch on capacitive touchscreen system - Google Patents

Description

Capacitive touch screen system and method for detecting touch on capacitive touch screen system

The various embodiments of the invention described herein are generally in the field of capacitive sensing input devices, and more particularly in relation to touch screens having an LCD display or other type of image display underneath. Multiple simultaneous or near simultaneous touch mutual capacitance measurement or sensing systems, devices, components, and methods.

U.S. Patent Application Serial No. 12/792,670, the entire disclosure of which is hereby incorporated by reference in its entirety in its entirety in the entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire all

Two major capacitive sensing and measurement techniques are currently used in most touchpad and touchscreen devices. The first such technique is self-capacitance. Used by many devices being fabricated from SYNAPTICS ^TM capacitance measurement techniques, such as devices based PSOC. ^TM of integrated circuit (IC) so as CYPRESS. The self-capacitance is directed to measuring a series of electrode pads using techniques such as those described in U.S. Patent No. 5,543,588, the entire disclosure of which is incorporated herein by reference. Self capacitance.

The self capacitance can be measured by detecting the amount of charge (Q = CV) accumulated on the object held at a given voltage. The self capacitance is typically measured by applying a known voltage to the electrodes and then using a circuit to measure the amount of charge flowing to the same electrode. When the external object approaches the electrode, the extra charge is attracted to The electrode. As a result, the self-capacitance of the electrode increases. Many touch sensors are configured such that the grounded object is a finger. The surface of the human body for the disappearance of the electric field is essentially a capacitor and typically has a capacitance of about 100 pF.

The electrodes in a self-capacitive touch panel are typically arranged in columns and rows. By scanning the first column and then the scan line, the location of the individual disturbances induced by, for example, the presence of a finger can be determined. However, in order to achieve accurate multi-touch measurements in the touchpad, it may be necessary to measure several finger touches simultaneously. In this case, the column and row techniques used for self-capacitance measurements can lead to uncertain results.

One way in which the number of electrodes can be reduced in a self-capacitance system is by staggering the electrodes in a sawtooth pattern. This interleaving produces a larger area of the finger that is sensed by a finite number of adjacent electrodes, allowing for better interpolation and therefore fewer electrodes. Such patterns may be particularly effective in one-dimensional sensors, such as those used in IPOD point selection trays. See, for example, U.S. Patent No. 6,879,930 to Sinclair et al., entitled "Capacitance touch slider", dated April 12, 2005.

The second major capacitive sensing and metrology technique used in touchpads and touchscreen devices is the mutual capacitance technique, in which the cross grid of electrodes is used to perform the measurement. See, for example, U.S. Patent No. 5,861,875, entitled "Methods and Apparatus for Data Input," by Gerpheide, dated Jan. 19, 1999. Technique using mutual capacitance touch panel device being fabricated in the CIRQUE ^TM. In contrast to measuring the capacitance of a single conductor and the capacitance can be measured by self-capacitance, which is affected by other objects close to the conductor, in the mutual capacitance measurement, the capacitance between the two conductors is measured.

In some mutual capacitance measuring systems, the sensing electrode array is disposed on a first side of the substrate, and the driving electrode array is disposed on a second side of the substrate opposite to the first side, the driving electrode array One of the rows or columns of electrodes is driven to a particular voltage, the mutual capacitance of a single column (or row) of the array of sense electrodes is measured, and the capacitance at a single column-row intersection is determined. By scanning all columns and rows, a capacitance map can be generated for all nodes in the grid. When a user's finger or other conductive object approaches a given grid point, some of the electric field lines originating from or near the grid point are deflected, thereby reducing the two points at the grid point The mutual capacitance of the electrodes. Since each measurement only detects a single mesh intersection, measurement uncertainty does not occur with multiple touches as in some self-capacitance systems. In addition, it is possible to measure a grid with n × n intersection points by only 2n pins on the IC.

The following situations are well known: accurately measuring the position of multiple finger touches on a capacitive touch screen simultaneously or nearly simultaneously is difficult and often unsuccessful.

There is a need for a capacitive measurement system that can be used in touch screen and trackpad applications that can accurately, reliably, and quickly between multiple simultaneous or near simultaneous touches on a capacitive touch screen. the difference.

In one embodiment, a capacitive touch screen system is provided, comprising: a touch screen comprising a first plurality of traces arranged in columns or rows and arranged to be aligned with respect to the first plurality of electrodes a second plurality of traces of the columns or rows of the columns or rows, the mutual capacitance being present between the first plurality of traces and the second plurality of traces at the first plurality Where the traces intersect the second plurality of traces, the mutual capacitance is present Changing in proximity to one or more of the fingers; a first drive sensing circuit, each of the first drive sensing circuits being operatively coupled to the first plurality of tracks by a switching circuit Corresponding to one of the lines, each first drive sensing circuit is operatively coupled to its respective trace and to a first amplifier, a first capacitor operatively coupled to one of the first amplifiers An input terminal and a first output terminal are coupled to a first comparator operatively coupled to the first output terminal of the first amplifier; a second drive sensing circuit, the second Each of the drive sensing circuits is operatively coupled to a respective one of the second plurality of traces by a switching circuit, each second drive sensing circuit being operatively coupled to its respective trace and a second amplifier operatively coupled to one of the second negative input and the second output of the second amplifier and coupled to a second comparator operatively coupled To the second output of the second amplifier; a drive/sense processor operatively coupled to the first drive sense circuits and the second drive sense circuits, respectively, and configured to: (a) control the first plurality The first driving sensing circuit drives at least some of the first plurality of traces, and controls the second plurality of second driving sensing circuits to sense at least one of the mutual capacitances via the second plurality of traces And (b) controlling the second drive sensing circuits to drive at least some of the second plurality of traces, and controlling the first drive sensing circuits to sense the first plurality of traces via the first plurality of traces At least some of the mutual capacitance.

In another embodiment, a method for detecting a touch on a capacitive touch screen system is provided, the capacitive touch screen system comprising: a touch a control screen comprising a first plurality of traces arranged in columns or rows and a second plurality of columns or rows arranged in an array with respect to the first plurality of electrodes or at an angle to the rows a trace, a mutual capacitance exists between the first plurality of traces and the second plurality of traces at a position where the first plurality of traces intersect the second plurality of traces, and the mutual capacitance is Changing in the presence of one or more of the fingers; a first drive sensing circuit, each of the first drive sensing circuits being operatively coupled to the first plurality of tracks by a switching circuit Corresponding to one of the lines, each first drive sensing circuit is operatively coupled to its respective trace and to a first amplifier, a first capacitor operatively coupled to one of the first amplifiers An input terminal and a first output terminal are coupled to a first comparator operatively coupled to the first output terminal of the first amplifier; a second drive sensing circuit, the second Each of the drive sensing circuits is operatively operable by the switching circuit Connected to one of the second plurality of traces, each second drive sensing circuit is operatively coupled to its respective trace and a second amplifier, a second capacitor operatively coupled to the second a second negative input terminal and a second output terminal of the amplifier, and connected to a second comparator operatively connected to the second output end of the second amplifier; and a driving/sensing Measuring processor operatively coupled to the first drive sensing circuits and the second drive sensing circuits, respectively, and configured to: (i) control the first drive sensing circuits Driving at least some of the first plurality of traces, and controlling the second drive sensing circuits to sense at least some of the mutual capacitances via the second plurality of traces, and (ii) controlling the Two drive sensing circuits drive the second plurality At least some of the traces, and controlling the first drive sensing circuits to sense at least some of the mutual capacitances via the first plurality of traces, the method comprising: driving via the first drive sensing circuits The first plurality of traces; sensing the mutual capacitance via the second plurality of traces and the second drive sensing circuits; driving the second plurality of traces via the second drive sensing circuits; Sensing the mutual capacitances via the first plurality of traces and the first driving sensing circuits; and detecting one of the touch screens based on the sensed mutual capacitance exceeding a predetermined voltage threshold Or the location of multiple touches.

Other embodiments are disclosed herein, and will be apparent to those skilled in the <RTIgt;

Different aspects of the various embodiments of the invention will be apparent from the description, drawings and claims.

The drawings are not necessarily to scale. Like numbers refer to like parts or steps throughout the drawings.

As illustrated in FIG. 1 , the capacitive touch screen system 110 is generally composed of an underlying LCD or OLED display 112 , an overlying touch sensitive panel or a touch screen 90 , and a touch screen 90 . A protective cover or dielectric board 95, and a touch screen controller, a microprocessor, an application specific integrated circuit ("ASIC") or a CPU 100. It should be noted that an image display other than an LCD or OLED can be disposed under the display 112.

2 shows a block diagram of one embodiment of a touch screen controller 100. In one embodiment, the touch screen controller 100 may be presented in accordance with the teachings herein, the modified Avago Technologies ^TM of AMRI-5000 ASIC 100 or wafer. In one embodiment, the touch screen controller is a low power capacitive touch panel controller designed to provide a touch screen system with high accuracy on-screen navigation.

The capacitive touch screen or touch panel 90 shown in FIGS. 3 and 4 can be formed by coating a conductive material such as indium tin oxide (ITO) onto the surface(s) of the dielectric board. The dielectric board typically comprises glass, plastic or another suitable electrically insulating and preferably light transmissive material and is typically configured in the shape of an electrode grid. The capacitance of the grid maintains charge and the finger is touched by the panel to present a circuit path to the user's body, which causes a change in the capacitance.

The touch screen controller 100 senses and analyzes the coordinates of these capacitance changes. When the touch screen 90 is attached to a display having a graphical user interface, it is possible to perform on-screen navigation by tracking the touch coordinates. It is often necessary to detect multiple touches. The size of the grid is driven by the resolution of the touch. Typically, an additional cover plate 95 is present to protect the top ITO layer of the touch screen 90 to form a complete touch screen solution (see, for example, Figure 1).

One way to create the touch screen 90 is to apply an ITO grid to only one side of the dielectric board or substrate. When the touch screen 90 is mated with the display, no additional protective cover is required. This situation has the benefit of producing a thinner display system with improved transmittance (>90%) to achieve a brighter and lighter handheld device. Applications for touch screen controller 100 include, but are not limited to, smart phones, portable media players, mobile internet devices (MIDs), and GPS devices.

Referring now to Figures 3 and 4, in one embodiment, a touch screen controller The 100 includes an analog front end having nine sense and drive signal lines connected to the ITO grid on the touch screen and 16 drive and sense lines. The touch screen controller 100 applies an excitation such as a square wave, a meander signal, or other suitable type of drive signal to the drive electrode, the excitation having a frequency selected from the range between about 40 kHz and about 200 kHz. . The AC signal is coupled to the sense line via a mutual capacitance. Touch panel 90 with your finger to change the capacitance at the touch location. The touch screen controller 100 can simultaneously analyze and track multiple touches. The high regeneration rate allows the host to track fast touches and any additional movements without noticeable delays. The embedded processor filters the data, identifies touch coordinates, and reports the coordinates to the host. The embedded firmware can be updated via patch loading. Of course, other numbers of drive and sense lines are contemplated, such as 8x12 and 12x20 arrays.

Touch screen controller 100 features multiple modes of operation with varying power consumption levels. In the dormant mode, controller 100 periodically looks for a touch at a rate programmed by the rest rate register. There are multiple sleep modes each having a continuously reduced power consumption. In the event that there is no touch duration for a certain time interval, the controller 100 automatically switches to the next low power consumption mode. However, as power consumption decreases, the response time to touch increases.

According to an embodiment and as shown in FIG. 9, the ITO grid on the touch screen 90 includes a plurality of columns 20a-20p (or Y lines 1-16) and a plurality of rows 10a-10i (or X lines 1 - 9), wherein columns 20a-20p are operatively coupled to second drive sensing circuitry 40b/50b and rows 10a-10i are operatively coupled to first sense drive circuitry 40a/50a. Figure 4 shows the wiring of ITO driving and sensing lines to touch One of the configurations of the screen controller 100.

Those skilled in the art will appreciate that touch screen controllers other than the modified AMR1-5000 wafer or touch screen controller 100, without departing from the scope or spirit of the various embodiments of the present invention, A microprocessor, ASIC or CPU can be used in the touchscreen system 110 and can use a different number of drive and sense lines and different numbers and groups than their drive and sense lines and drive and sense electrodes as explicitly demonstrated herein. Drive and sense electrodes.

Referring now to FIG. 5, an embodiment of a capacitive touch screen system 110 including a touch screen 90 and a touch screen controller 100 is shown. As shown, the touch screen controller 100 includes a drive/sense processor 102, first drive sense circuits 40a/50a, and second drive sense circuits 40b/50b. The drive sensing circuits 40a/50a are operatively coupled to the first plurality of traces 10a-10i of the touchscreen 90 (lines 1-9 in Figure 9). The drive sensing circuits 40b/50b are operatively coupled to the second plurality of traces 20a-20p of the touchscreen 90 (lines 1-16 in Figure 9). As shown in FIG. 4, FIG. 5 and FIG. 9, the touch screen 90 includes a first plurality of traces 10a-10i (corresponding to X lines 1-9 respectively) arranged in columns or rows, and arranged in relation to The columns of the first plurality of traces 10a-10i or the second plurality of traces 20a-20p of the rows or rows of the rows arranged at an angle (corresponding to Y-lines 1-16, respectively). A mutual capacitance 30 (see FIGS. 7 and 9) exists between the first plurality of traces 10a-10i and the second plurality of traces 20a-20p at the first plurality of traces and the second plurality At the location where the traces intersect, the mutual capacitance 30 changes in the presence of one or more fingers.

A first drive sensing circuit 40a/50a operatively coupled to the first plurality of traces 10a-10i is provided. The first drive sensing circuit 40a/50a includes a set of individual switching and amplifying circuits 42a, which in turn are individually followed by a corresponding set of comparators 44a. Each of the first drive sensing circuits 40a/50a is operatively coupled to one of the first plurality of traces or lines 10a-10i, each first drive sensing circuit comprising an operatively coupled a switching circuit to the corresponding trace on the touch screen 90 and connected to the amplifier and a capacitor connected to the output and the negative input of the amplifier (see 42a in FIG. 5) and connected to the comparator, the comparator It is operatively coupled to the output of the amplifier (see 44a in Figure 5).

A second drive sensing circuit 40b/50b operatively coupled to the second plurality of traces 20a-20i is provided. The second drive sensing circuit 40b/50b includes a set of individual switching and amplifying circuits 42b, which in turn are followed by a set of individual comparators 44b. Each of the second drive sensing circuits 40b/50b is operatively coupled to one of the second plurality of traces 20a-20p, each second drive sensing circuit including an operatively coupled touch The corresponding trace on the control screen 90 is connected to the switching circuit of the amplifier and to the output and negative input of the amplifier (see 42b in FIG. 5) and to the capacitor of the comparator, the comparator is operable Ground is connected to the output of the amplifier (see 44b in Figure 5).

6 shows one of many possible embodiments of one of the circuits of sense drive circuit 40a/50a or 40b/50b of FIG. As shown, circuit 43 includes operational amplifier 45 and feedback capacitor 46, sample and hold circuit 47, comparator 48, and flip-flop 49. Also covers the use of suitable electrical and / or electronic groups Other embodiments of the circuit 43 and the sensing drive circuits 40a/50a and 40b/50b that achieve the same or substantially the same functionality, as will be appreciated by those skilled in the art.

As further shown in FIG. 5, a drive/sense processor 102 that preferably (but not necessarily) forms part of a touch screen controller 100 (which is preferably a wafer, integrated circuit or ASIC) is operatively coupled to First drive sensing circuit 40a/50a and second drive sense circuit 40b/50b, and configured to: (a) control first drive sense circuit 40a/50a to drive the first plurality of traces At least some of 10a-10i, and controlling second drive sensing circuit 40b/50b to sense at least some of mutual capacitance 30 via the second plurality of traces 20a-20p, and (b) controlling second drive sensing The circuit 40b/50b drives at least some of the second plurality of traces 20a-20p and controls the first drive sensing circuit 40a/50a to sense at least one of the mutual capacitances 30 via the first plurality of traces 10a-10i some.

5, 6 and 7 further show that the first drive sensing circuit 40a/50a and the second drive sensing circuit 40b/50b can comprise a circuit 43 (for an individual sense drive circuit, which is disposed in the circuit 40a/ 50a and 40b/50b), the capacitors in the first drive sensing circuit 40a/50a and the second drive sensing circuit 40b/50b may include sample and hold capacitor circuits 46 and 47, and may further include logic circuits, the logic The circuitry is configured to permit each of the first drive sense circuit 40a/50a and the second drive sense circuit 40b/50b to operate in a selectable and interchangeable manner under the control of the drive/sense processor 102 The driving circuit or the operation is a sensing circuit. It should be noted that the drive/sense processor 102 can be configured to control the first drive sense circuit 40a/50a or the second drive sense Circuitry 40b/50b such that the traces in the first plurality of traces 10a-10i or the second plurality of traces 20a-20p can be driven substantially simultaneously, and such that the first plurality of traces 10a- The traces in 10i or the second plurality of traces 20a-20p may be sensed substantially simultaneously. It should be further noted that the amplifiers in the individual drive sensing circuits can be configured to operate as a follower, wherein no capacitance is placed in the feedback loop of the amplifier when the drive sense circuit is configured as a driver circuit. These follower configurations of the drive sensing circuit can be implemented using suitable switching and logic circuits.

Referring now to Figures 5 and 6, each of the first plurality of drive sensing circuits 40a/50a and the comparators of the comparator sets 44a and 44b of the second plurality of drive sensing circuits 40b/50b It was configured to detect the voltage corresponding thereto is associated with the mutual capacitance 30 at a predetermined threshold voltage V _t. At least some of the first plurality of drive sense circuits 40a/50a and the comparators of the comparator sets 44a and 44b of the second plurality of drive sense circuits 40b/50b may also be configured to be at a predetermined high The voltage associated with its respective mutual capacitance 30 is detected at a voltage threshold and a predetermined low voltage threshold. In addition, the drive/sense processor 102 can be further configured to control the first drive sense circuit 40a/50a and the second drive sense circuit 40b/50b to substantially simultaneously sense multiple mutuals on the touch screen 90. Capacitance, or detecting multiple simultaneous or near simultaneous touch locations on the touch screen 90, more details regarding this are set forth below. Detection of the locations on the touchscreen 90 can be accomplished using comparator groups 44a and 44b to detect voltages associated with mutual capacitances 30 corresponding to locations of multiple simultaneous or near simultaneous touches, as set forth below. More details on this. The drive/sense processor 102 can be further configured to control driving the first plurality of traces 10a-10i and the second plurality of traces 20a-20p based on the detected position of the touch A plurality of selected persons, and/or a plurality of selected ones of the sensing mutual capacitances 30 are controlled based on the detected positions of the touches, and more details regarding this are set forth below. The drive/sense processor 102 can also be configured to generate a tag associated with the location of the detected touch and/or generate a tag associated with the magnitude of the detected touch, as set forth below. More details on this.

In one embodiment, the angle between the first plurality of traces 10a-10i and the second plurality of traces 20a-20p is about 90 degrees, but can be, for example, about 15 degrees, about 30 degrees, about 45 degrees. Any suitable angle of degree, about 60 degrees or about 75 degrees. The first plurality of traces 10a-10i and the second plurality of traces 20a-20p may be respectively disposed in a first plane and a second plane that are substantially parallel but offset in a vertical direction, or may be disposed in the substantial On the same plane. In one embodiment, the first plurality of traces 10a-10i and the second plurality of traces 20a-20p comprise indium tin oxide ("ITO") or any other suitable electrically conductive material. A liquid crystal display or any other suitable image display can be disposed under the first plurality of traces 10a-10i and the second plurality of traces 20a-20p. The first plurality of traces 10a-10i and the second plurality of traces 20a-20p are preferably disposed on a substantially optically transparent substrate comprising an electrically insulating material.

It should be noted that the touchscreen system 110 can be incorporated into or form part of one of the following: LCD, computer display, laptop, personal data assistant (PDA), mobile phone, radio, MP3 player, Portable music player, fixed device, TV, stereo (stereo), exercise machine, industrial control, control panel, outdoor control device, Household appliances, or any other suitable electronic device.

In another embodiment, a method of detecting a touch on a capacitive touch screen system is provided, comprising: (a) driving the first plurality of traces 10a via a first drive sensing circuit 40a/50a -10i; (b) sensing the mutual capacitance 30 via the second plurality of traces 20a-20p and the second drive sensing circuit 40b/50b; (c) driving the second via the second drive sensing circuit 40b/50b a plurality of traces 20a-20p; (d) sensing the mutual capacitance 30 via the first plurality of traces 10a-10i and the first drive sensing circuit 40a/50a; and (e) exceeding a predetermined voltage threshold The sensing mutual capacitance is used to detect the position of one or more touches on the touch screen 90.

The method can further include: driving the first plurality of traces 10a-10i substantially simultaneously via the first drive sensing circuit 40a/50a; driving the second plurality of substantially simultaneously via the second drive sensing circuit 40b/50b Traces 20a-20p; substantially simultaneously sensing at least some of the mutual capacitances 30 via the first drive sensing circuits 40a/50a; and/or substantially simultaneously sensing the mutual capacitances 30 via the second drive sensing circuits 40b/50b At least some of them. It should be noted that sensing can include detecting a voltage associated with the mutual capacitance 30.

In an embodiment, a method may further include: detecting, by the comparator group 44a and/or 44b, a plurality of simultaneous or near simultaneous touch positions on the touch screen 90; detecting and interacting with the positions corresponding to the positions a voltage associated with the capacitor 30; driving a plurality of selected ones of the first driving sensing circuit 40a/50a and the second driving sensing circuit 40b/50b based on the detected position of the touch; Sensing a plurality of selected ones of the first driving sensing circuit 40a/50a and the second driving sensing circuit 40b/50b based on the position of the touch; Generating a tag associated with the detected location of the touch; and generating a tag associated with the magnitude of the detected touch.

Referring now to Figure 7, an embodiment of the individual components of the first drive sensing circuit 40a/50a and the second drive sensing circuit 40b/50b is shown. As illustrated, the first plurality of traces 10a-10i (X lines 1-9) and the second plurality of traces 20a-20p (Y lines 1) disposed along the X and Y axes (see FIG. 9) are used. A plurality of selected ones of -16) connect the two drive sensing circuits 40a/50a and 40b/50b via a single mutual capacitance 30. As a result, the mutual capacitance 30 in FIG. 7 represents a single cross-coupling capacitor at a single intersection of a plurality of selected ones of the first plurality of traces 10 and the second plurality of traces 20, wherein the mutual capacitance 30 The magnitude depends on the presence or absence of a finger on the touch screen 90 that is close to the mutual capacitance 30. One of the individual drive sensing circuits of the drive sense circuit 40a/50a or 40b/50b of FIG. 7 is selected to drive the selected one of the traces 10a-10i or 20a-20p, and another one of FIG. 7 is selected. The sense circuits 40a/50a or 40b/50b are driven to sense selected lines from among the traces 10a-10i or 20a-20p via the mutual capacitance 30. Each of the individual drive sensing circuits 40a/50a or 40b/50b shown in Figure 7 is a charge accumulator circuit having sample and hold capacitors that can be turned off or by the collected charge. Keep floating and available for further processing. When each of the amplifiers used in the charge accumulator circuit is used as a touch screen line or trace driver, the output of the amplifier and the inverting input are stored. The virtual ground of each charge accumulator circuit can be coupled to a low drive potential and a high drive potential for both the sense mode of operation and the drive mode of operation. In an embodiment, the individual circuits 40a/50a are configured using the simple logic circuit shown in FIG. Each of 40b/50b operates in a sensing, storage and drive mode in an interchangeable and selectable manner. After being charged as a negative feedback element, the capacitors in each of the drive sensing circuits 40a/50a or 40b/50b can be turned off for storing the collected charge when the respective amplifiers are switched to the drive mode. One embodiment of a command sequence that permits the sensing and driving of logic control for signals of the circuits shown in FIG. 7 is shown in FIG. When a logic signal high state is presented with a given switch drive, the switch corresponding to the given switch drive is closed.

Referring now to Figure 9, a 9 x 16 touch screen 90 comprising a first plurality of traces 10a through 10i (X lines 1-9) and a second plurality of traces 20a through 20p (Y lines 1-16) is shown. An embodiment. In one embodiment, when no finger touch is made on the touch screen 90, the mutual capacitance 30 (or driving to the sensing capacitor) of each pixel on the touch screen 90 each has a capacitance of about 1 pF. In the presence of a finger touch on the touch screen 90, these mutual capacitances change to about 0.7 pF. In FIG. 9, each finger touch on touch screen 90 causes a change in mutual capacitance 30 disposed within a 2x2 pixel cluster.

In one embodiment, the sensing, driving, and pre-processing of signals provided by touch screen 90 and from touch screen 90 follows the drive and sensing protocols discussed below. Referring to the block diagram shown in FIG. 5, the processing of the signal provided by the touch screen 90 (caused by the driving signal to the touch screen 90) and the sensing of the signal (by the proximity touch screen) are described. 90 placement of one or more fingers caused by).

In one embodiment, the driving of the touch screen 90 begins with the sensing driving circuit 40a/50a driving all of the X lines 1-9 (the first plurality of traces 10a-10i), the same The charge is acquired in the charge accumulator circuit of the sense drive circuit 40b/50b operatively connected to the Y lines 1-16 (the second plurality of traces 20a-20p), and then the Y line signal is then stored to The holding capacitors of the drive circuit 40b/50b are sensed. It should be noted that the integrating capacitors described above can be used for signal storage. During driving, the drive sensing circuits 40a/50a are operatively coupled to the X-rays 1-9 while configured in the buffer mode, while the sense drive circuits 40b/50b are configured in the accumulator mode. In this case, it is operatively connected to the Y line. The virtual grounds of the sense drive circuits 40a/40b and 40b/50b, which are operatively coupled to the X and Y lines, respectively, are coupled to respective low and high levels of drive potential. The sense command sequence is similar to the sense command sequence described for the circuits described above in connection with FIGS. 7 and 8.

The charge data corresponding to the Y line signal acquired in the capacitor of the sense drive circuit 40b/50b is connected to a comparator whose potential is presented to the comparator group 44b, wherein a signal exceeding a predetermined threshold value V _t is detected. As described above, FIG. 6 shows an embodiment of a single sense drive circuit configured to sense the signals and present the signals to a comparator 48 corresponding thereto. While the data of the detected Y line signal is presented to the comparator, the acquisition or sensing of the X-ray signal can be initiated by configuring the sensing drive circuit 40b operatively connected to the Y line. 50b for operating in the drive mode and applying a drive signal to all of the Y lines while simultaneously taking charge into the sense drive circuit 40a/50a configured to be operatively coupled to the X-line charge accumulator circuit .

In order to detect the positions of a plurality of simultaneous or near simultaneous finger touches 61, 62, 63, 64, and 65 performed on the touch screen 90 of FIG. 9, the touches in FIG. The ten simulated continuous sensing and driving cycles performed by the X-axis and the Y-axis of the control screen 90 are illustrated as histograms in FIGS. 10-19, which correspond to loops 1 through 10, respectively. As will be seen by reference to the histograms, the overlapping and non-overlapping touches sensed along the X and Y axes correspond to a plurality of sensed touches and are thus clearly visible.

Referring to the histograms of the sensed touch signals as shown in Figures 9 and 10 through 19, it will be seen that for the X-axis sensed signals, the two touches overlap along the same X-ray (see placement along X-lines 4 and 5). Touches 62 and 65), and for the sensed signal of the Y-axis, one touch overlaps along the same Y line (see touches 62 and 63 placed along lines 3 and 4). The touch area of each touch occupies an area of two pixels by two pixels. Other processing is based on selection criteria that characterize the sensing program as two adjacent touch signals that exceed a predetermined threshold Vt. More advanced processing criteria can also be used to select signal processing regions of interest using sensed signals that exceed different voltage thresholds, such as window comparisons (above low threshold V _tL and below high threshold V) _tH ). In order to clearly disentangle non-overlapping touches using signals sensed along the X and Y axes, different or modified selection criteria can be used. However, a relatively simple touch sensing method or algorithm is described in detail below.

As mentioned above, the touch sensing method or algorithm described below is based on the selection of the region of interest with a region of 2 pixels by 2 pixels, wherein the adjacent sensed signals exceed a predetermined signal threshold. V _t . Examples of the sense of touch sensing are discussed in further detail herein, V _t is chosen to 0.5V. It should be noted that the processing of different combinations of different sensed readout lines in conjunction with the sensed signals can be used to separate multiple finger touches that occur close to each other.

As shown in FIG. 9, a plurality of simultaneous or near simultaneous touches 61-65 are located at different coordinates or locations on the touchscreen 90. The touch 61 is located at the pixel or touch screen position X (2, 3), Y (2, 3). The touch 62 is located at the pixel or touch screen position X (4, 5), Y (4, 5). The touch 63 is located at the pixel or touch screen position X (7, 8), Y (4, 5). Touch 64 is located at pixel or touch screen position X (7, 8), Y (7, 8). The touch 65 is located at the pixel or touch screen position X (4, 5), Y (14, 15).

Figure 10 shows the results of simultaneously driving all Y lines while cycling all of the X lines during Cycle 1. As shown in FIG. 10, the touches 61, 62, and 65 and 63 and 64 are detected by the first sensing driving circuit 40a/50a because the touches are caused by the first driving sensing circuit 40a/50a. sensing threshold exceeds 0.5 volts (or V _t) signal. As further shown in FIG. 10, touch 61 is the only touch placed along X-rays 2 and 3, and thus is compared to the higher amplitude signal detected on X-rays 4 and 5 (which corresponds to along X-ray 4) And 5 sets of multiple touches 62 and 65) and higher amplitude signals detected on X lines 7 and 8 (which correspond to multiple touches 63 and 64 placed along X lines 7 and 8), causing staying The lower amplitude signal detected on X lines 2 and 3. After loop 1 has been completed, it is not possible to determine which of the touches 61, 62, 63, 64, and 65 corresponds to the unique X, Y position on the touch screen 90.

Figure 11 shows the result of simultaneously driving all X-rays while cycling all of the Y-lines during Cycle 2. As shown in FIG. 11, the touches 61, 62 and 63 and 63 and 65 are detected by the second sensing driving circuit 40b/50b, because the touches are caused by the second driving sensing circuit 40b/50b sensing threshold exceeds 0.5 volts (or V _t) signal. As further shown in FIG. 11, touches 61, 64, and 65 are compared to the higher amplitude signals detected on Y lines 4 and 5 (which correspond to the plurality of touches 62 and 63 disposed along Y lines 4 and 5). A lower amplitude signal to be detected on Y lines 2 and 3, 7 and 8 and 14 and 15 respectively. After only cycles 1 and 2 have been completed, it is still not possible to determine which of the touches 61, 62, 63, 64, and 65 corresponds to which X, Y positions on the touch screen 90. However, the information obtained during the cycles 1 and 2 that has been presented to the drive/sense processor 102 is used by the drive/sense processor 102 to determine that the selected X-ray and Y should be subsequently driven and sensed during Cycle 3. Which of the lines are such that a program that determines the exact and unique (X, Y) position of each of the individual touches can begin.

Referring now to Figure 12, it is shown that by driving only X-rays 2 and 3 (the lines have been selected to be based on the sensed signals by the drive/sense processor 102 and their respective positions determined in cycles 1 and 2). Drive) and sense the results obtained by all Y lines. As a result, during the cycle 3 determines a touch position 61 occurs in the Y-Y (2,3) and touch-61 corresponds to just exceed the threshold voltage V _t of the sensed signal.

Loop 4 of Figure 13 follows loop 3. Figure 13 shows that by driving only Y lines 2 and 3 (the lines have been selected to be driven by the drive/sense processor 102 based on the sensed signals and their respective positions determined in cycles 1, 2 and 3) And sensing the results obtained by all X-rays. As a result, during cycle 4 61 determines the touch occurs at the position X X (2,3) and touch-61 corresponds to just exceed the threshold voltage V _t of the sensed signal. The cluster X, Y coordinates of touch 61 are now determined by the sensing/driving processor 102, and the data corresponding to the cluster coordinates is multiplexed for parallel digitization and self-driving/sensing processor 102 to touch Other processing of the screen controller 100.

The drive/sense processor 102 again analyzes the sensed data that has been rendered to it by the sense drive circuits 40a/50a and 40b/50b during the previous cycle, and continues to indicate the sense drive circuit 40a/50a in cycle 5. The X lines 3 and 4 are driven and the sensing drive circuit 40b/50b is instructed to sense all of the Y lines. The results of this particular sequence of drive and sense commands are shown in FIG. 14, where it will be seen that none of the signals sensed by sense drive circuitry 40b/50b trigger a threshold voltage equal to or greater than any threshold along any Y-line. Detection of any voltage of _t . As a result, during loop 5, no data corresponding to any detected cluster coordinates is transmitted from the drive/sense processor 102 to the touch screen controller 100.

The drive/sense processor 102 again analyzes the sensed data that has been rendered to it during the previous cycles 1 through 5 by the sense drive circuits 40a/50a and 40b/50b, and in loop 6, the drive/sense processor 102 instructs the sense drive circuit 40a/50a to drive the X lines 4 and 5 and instructs the sense drive circuit 40b/50b to sense all of the Y lines. The results of this particular sequence of drive and sense commands are shown in Figure 15, where it will be seen that threshold voltages are detected along lines Y and 5 and along lines 14 and 15, which correspond to edges along Y, respectively. A single touch 62 disposed along lines 4 and 5 and a single touch 65 disposed along lines 14 and 15 are provided.

The result of loop 6 is that the drive/sense processor 102 identifies another region of interest for subsequent drive and sense signals, and the drive/sense processor 102 indicates the sense drive circuit 40b/50b during loop 7. The Y lines 4 and 5 are driven and the sensing drive circuit 40a/50a is instructed to sense all of the X lines. Figure 16 shows the results of the command, drive, and sense of Cycle 7, which are due to the detection of the threshold voltage V _t along X-rays 4 and 5 and 7 and 8, respectively, at the X coordinate X (4, 5) and Touches 62 and 63 are detected at X (7, 8). However, sufficient information is not provided during loop 7 to permit the sensing and drive processor 102 to determine the unique and precise X, Y position of touches 62 and 63.

Thus, during cycle 8, drive/sense processor 102 instructs sense drive circuit 40b/50b to drive Y lines 14 and 15 and instructs sense drive circuit 40a/50a to sense all of the X lines. The results of this particular sequence of drive and sense commands are shown in Figure 17, where it will be seen that threshold voltages are detected along only X lines 4 and 5, which correspond to X and 4 and X lines along X lines. 14 and 15 placement touch 65. Thus, the unique and precise position of the touch 65 is determined during the loop 8 by the drive/sense processor 102. Due to the information obtained during cycles 1 through 8, the unique and precise position of touch 62 is also determined during cycle 8 by drive/sense processor 102. The data corresponding to the cluster X, Y coordinates of the touches 62 and 65 determined by the sensing/driving processor 102 during the loop 8 are multiplexed for parallel digitization and self-driving/sensing processor 102 to touch Other processing of the screen controller 100.

The drive/sense processor 102 again analyzes the sensed data that has been rendered to it during the previous cycles 1 through 8 by the sense drive circuits 40a/50a and 40b/50b, and in loop 9, the drive/sense processor 102 instructs the sense drive circuit 40a/50a to drive the X lines 7 and 8 and instructs the sense drive circuit 40b/50b to sense all of the Y lines. The results of this particular sequence of drive and sense commands are shown in Figure 18, where it will be seen that threshold voltages are detected along lines Y and 5 and along lines Y and 8 which correspond to the edge along Y. A single touch 63 placed along lines 4 and 5 and a single touch 64 placed along lines 7 and 8. However, sufficient information is not provided during loop 9 to permit the sensing and drive processor 102 to determine the unique and precise X, Y position of touches 63 and 64.

Thus, during cycle 10, drive/sense processor 102 instructs sense drive circuit 40b/50b to drive Y lines 7 and 8 and instructs sense drive circuit 40a/50a to sense all of the X lines. The results of this particular sequence of drive and sense commands are shown in FIG. 19, where it will be seen that threshold voltages are detected along only X lines 7 and 8, which correspond to X lines 7 and 8 and Y lines. 7 and 8 placement touch 64. Thus, the unique and precise location of the touch 64 is determined during the cycle 10 by the drive/sense processor 102. Due to the information obtained during cycles 1 through 9, the unique and precise position of touch 63 is also determined during cycle 10 by drive/sense processor 102. Corresponding to the cluster X, Y coordinates of the touches 63 and 64 determined by the sensing/driving processor 102 during the loop 8 are multiplexed for parallel digitization and self-driving/sensing processor 102 to touch Other processing of the screen controller 100.

It should be noted that the various teachings presented herein are applicable to light transmissive or non-transmissive touch panels disposed on, for example, a printed circuit board, flex board, or other suitable substrate. Although the capacitive touch screen 90 is mainly used in the case of relatively small portable devices and thus touch panels and touch screens, it is also valuable in the case of larger devices. Larger devices include, for example, keyboards associated with desktop computers or other non-portable devices (such as exercise equipment, industrial control panels, home appliances, and the like). Similarly, although many embodiments of the invention are likely to be configured for manipulation by a user's fingers, some embodiments may be configured for manipulation by other mechanisms or body parts. For example, the present invention can be located on a hand pallet or a hand pallet of a keyboard and engaged by a user's hand. In addition, the capacitive touch screen system 110 and the capacitive touch type The various embodiments of the screen 90 are not limited in scope to the placement of the drive electrodes in a row and the sensing electrodes disposed in a row. The fact is that the columns and rows are interchangeable with respect to the sensing and driving electrodes. Various embodiments of the capacitive touch screen system 110 and the capacitive touch screen 90 can also be operated in conjunction with a stylus to detect stylus touch on the touch screen 90. System 110 and touch screen 90 can be further configured to permit detection of both finger touch and stylus touch.

It should be further noted that methods of making and having made the various components, devices, and systems described herein are within the scope of the present invention.

The embodiments described above are considered as examples of the invention and are not to be considered as limiting the scope of the invention. In addition to the foregoing embodiments of the invention, the embodiments of the invention, Therefore, many combinations, permutations, variations and modifications of the foregoing embodiments of the invention, which are not explicitly described herein, are still within the scope of the invention.

1‧‧‧X line/Y line

2‧‧‧X line/Y line

3‧‧‧X line/Y line

4‧‧‧X line/Y line

5‧‧‧X line/Y line

6‧‧‧X line/Y line

7‧‧‧X line/Y line

8‧‧‧X line/Y line

9‧‧‧X line/Y line

10‧‧‧ Trace/Y line

10a-10i‧‧‧ Traces/Lines

11‧‧‧Y line

12‧‧‧Y line

13‧‧‧Y line

14‧‧‧Y line

15‧‧‧Y line

16‧‧‧Y line

20‧‧‧ Traces

20a-20p‧‧‧ Traces/columns

30‧‧‧ mutual capacitance

40a/50a‧‧‧First drive sensing circuit

40b/50b‧‧‧second drive sensing circuit

42a‧‧‧Switching and amplifying circuit

42b‧‧‧Switching and amplifying circuit

43‧‧‧ Circuitry

44a‧‧‧ comparator

44b‧‧‧ comparator

45‧‧‧Operational Amplifier

46‧‧‧Feedback capacitor

47‧‧‧Sampling and holding circuit

48‧‧‧ Comparator

49‧‧‧Factor

61‧‧‧Touch

62‧‧‧Touch

63‧‧‧Touch

64‧‧‧Touch

65‧‧‧Touch

90‧‧‧Touch-sensitive panel or touch screen

95‧‧‧Protective cover or dielectric board

100‧‧‧Touch Screen Controller/Special Application Integrated Circuit ("ASIC") or CPU

102‧‧‧Drive/Sensor Processor

110‧‧‧Capacitive touch screen system

112‧‧‧LCD or OLED display

120‧‧‧Host Controller

1 shows a cross-sectional view of one embodiment of a capacitive touch screen system; FIG. 2 shows a block diagram of a capacitive touch screen controller; and FIG. 3 shows a block of a capacitive touch screen system and a host controller. FIG. 4 is a schematic block diagram showing an embodiment of a capacitive touch screen system; FIG. 5 is a block diagram showing an embodiment of a capacitive touch screen system; 6 shows an embodiment of a charge accumulator circuit and corresponding comparators; FIG. 7 shows an embodiment of a single drive sense circuit operatively coupled to each other via mutual capacitance on a touch screen; FIG. 8 shows a corresponding diagram Command logic signals for portions of the circuit shown in Figure 7; Figure 9 shows an embodiment of a capacitive touch screen, and Figures 10 through 19 show X-rays corresponding to the touch screen of Figure 9 or A histogram of the signal sensed by the Y line.

10a-10i‧‧‧ Traces/Lines

20a-20p‧‧‧ Traces/columns

40a/50a‧‧‧First drive sensing circuit

40b/50b‧‧‧second drive sensing circuit

42a‧‧‧Switching and amplifying circuit

42b‧‧‧Switching and amplifying circuit

44a‧‧‧ comparator

44b‧‧‧ comparator

90‧‧‧Touch-sensitive panel or touch screen

100‧‧‧Touch Screen Controller/Special Application Integrated Circuit ("ASIC") or CPU

102‧‧‧Drive/Sensor Processor

Claims (37)

A capacitive touch screen system comprising: a touch screen comprising a first plurality of traces arranged in columns or rows and arranged at an angle with respect to a column or row of the first plurality of electrodes a second plurality of traces of the column or row, the mutual capacitance exists between the first plurality of traces and the second plurality of traces, the first plurality of traces intersecting the second plurality of traces At a location, the mutual capacitance changes in the presence of one or more fingers or touch devices; a plurality of first drive sensing circuits, each of the first drive sensing circuits The first amplifier of each of the first drive sensing circuits is operatively coupled to its respective first plurality of switches by a switching circuit operatively coupled to one of the first plurality of traces One of the traces, a first capacitor operatively coupled to one of the first negative input and the first output of the first amplifier, and coupled to a first comparator, the first comparator operatively Connected to the first output of the first amplifier; a plurality of a second drive sensing circuit, each of the second drive sensing circuits being operatively coupled to a respective one of the second plurality of traces by a switching circuit, each of the second drive sensing The circuit is operatively coupled to one of the respective second plurality of traces and a second amplifier, a second capacitor operatively coupled to one of the second negative input of the second amplifier and a second output And connected to a second comparator operatively coupled to the second output of the second amplifier; a drive/sense processor operatively coupled to the first drive sense circuits and the second drive sense circuits, respectively, and configured to: (a) control the first Driving a sensing circuit to drive at least some of the first plurality of traces, and controlling the second driving sensing circuits to sense at least some of the mutual capacitances via the second plurality of traces, and (b) Controlling the second drive sensing circuits to drive at least some of the second plurality of traces, and controlling the first drive sensing circuits to sense at least some of the mutual capacitances via the first plurality of traces . The capacitive touch screen system of claim 1, wherein the first drive sensing circuits and the second drive sensing circuits comprise charge accumulator circuits. The capacitive touch screen system of claim 1, wherein the first capacitor and the second capacitor of the first driving sensing circuit and the second driving sensing circuit are sampling and holding capacitors. The capacitive touch screen system of claim 1, wherein each of the first drive sensing circuit and the second drive sensing circuits comprises a logic circuit configured to permit such Each of the first drive sensing circuit and the second drive sensing circuits operates in a selectable manner as a drive circuit or as a sense circuit. The capacitive touch screen system of claim 1, wherein the drive/sense processor is configured to control the first drive sensing circuits or the second drive sensing circuits such that the first plurality The traces or the second plurality of traces are substantially simultaneously driven. The capacitive touch screen system of claim 1, wherein the driving/sensing The processor is configured to control the first drive sense circuits or the second drive sense circuits such that the first plurality of traces or the second plurality of traces are substantially simultaneously sensed. The capacitive touch screen system of claim 1, wherein each of the first drive sensing circuits and the comparators of the second drive sensing circuits are configured to be in a predetermined A voltage associated with the corresponding mutual capacitance is detected at a voltage limit. The capacitive touch screen system of claim 1, wherein at least some of the first drive sensing circuits and the comparators of the second drive sensing circuits are configured to be at a predetermined high threshold The voltage associated with the corresponding mutual capacitance is detected at voltage and low threshold voltage. The capacitive touch screen system of claim 1, wherein the drive/sense processor is further configured to control the first drive sensing circuits and the second drive sensing circuits to sense the substantially simultaneously A plurality of the mutual capacitances on the touch screen. The capacitive touch screen system of claim 1, wherein the driving/sensing processor is further configured to control the first driving sensing circuit and the second driving sensing circuit to detect the touch Multiple simultaneous or near simultaneous touches on the screen. The capacitive touch screen system of claim 10, wherein the detection of the plurality of simultaneous or near simultaneous touch positions on the touch screen is detected and correlated with the mutual capacitance corresponding to the positions This comparator is implemented with the voltage of the junction. The capacitive touch screen system of claim 1, wherein the driving/sensing The processor is further configured to control driving the plurality of selected ones of the first plurality of traces and the second plurality of traces based on the locations of the detected touches. The capacitive touch screen system of claim 1, wherein the drive/sense processor is further configured to control the sensing of the mutual capacitance based on the positions of the detected touches Selected by. The capacitive touchscreen system of claim 1, wherein the drive/sense processor is further configured to generate a tag associated with the locations of the detected touches. The capacitive touchscreen system of claim 1, wherein the drive/sense processor is further configured to generate a tag associated with the magnitude of the detected touch. The capacitive touch screen system of claim 1, wherein the angle is about 90 degrees. The capacitive touch screen system of claim 1, wherein the first plurality of traces and the second plurality of traces are respectively disposed in a first plane and a second plane that are substantially parallel but offset in a vertical direction. in. The capacitive touch screen system of claim 1, wherein the first plurality of traces and the second plurality of traces are disposed in substantially the same plane. The capacitive touch screen system of claim 1, wherein the first plurality of traces and the second plurality of traces comprise indium tin oxide ("ITO"). The capacitive touch screen system of claim 1, wherein the first plurality of traces and the second plurality of traces form a 9×16 sensor array, an 8×12 sensor array, or a 12 ×20 sensor array. The capacitive touch screen system of claim 1, wherein a liquid crystal display is disposed under the first plurality of traces and the second plurality of traces. The capacitive touch screen system of claim 1, wherein an image display is disposed under the first plurality of traces and the second plurality of traces. The capacitive touch screen system of claim 1, wherein the first plurality of traces and the second plurality of traces are disposed on a substrate comprising an electrically insulating material. The capacitive touchscreen system of claim 21, wherein the substrate is substantially optically transparent. The capacitive touch screen system of claim 1, wherein the first driving sensing circuits and the second driving sensing circuits are incorporated into an integrated circuit. The capacitive touch screen system of claim 1, wherein the touch screen system is incorporated into or forms part of one of: an LCD, a computer display, a laptop, and a person profile. Assistant (PDA), a mobile phone, a radio, an MP3 player, a portable music player, a fixed device, a television, a stereo system, a training machine, an industrial control, a control panel An outdoor control device, a household appliance and an electronic device. A method for detecting a touch on a capacitive touch screen system, the capacitive touch screen system comprising: a touch screen comprising a first plurality of traces arranged in columns or rows and arranged in a mutual capacitance exists between the first plurality of traces and the second plurality of traces of the columns or rows of the first plurality of electrodes at an angular arrangement Between two complex traces at a position where the first plurality of traces intersect the second plurality of traces, the mutual capacitance is in the presence of one or more fingers or touch devices Changing; a plurality of first drive sensing circuits, each of the first drive sensing circuits being operatively coupled to a respective one of the first plurality of traces by a switching circuit, each of the a first drive sensing circuit operatively coupled to one of its respective first plurality of traces and coupled to a first amplifier, a first capacitor operatively coupled to one of the first amplifiers An input end and a first output end connected to a first comparator, the first comparator being operatively coupled to the first output end of the first amplifier; a plurality of second drive sensing circuits, Each of the second drive sensing circuits is operatively coupled to a respective one of the second plurality of traces by a switching circuit, each of the second drive sensing circuits being operatively coupled to its respective One of the second plurality of traces and one second a second capacitor operatively coupled to the second negative input and the second output of the second amplifier and coupled to a second comparator operatively coupled to the second a second output of the second amplifier; and a drive/sense processor operatively coupled to the first drive sense circuit and the second drive sense circuit, respectively, and configured to perform the following Operation: (i) controlling the first drive sensing circuits to drive at least some of the first plurality of traces, and controlling the second drive sensing circuits to sense the mutual via the second plurality of traces At least some of the capacitors, and (ii) controlling the second drive sensing circuits to drive at least some of the second plurality of traces and controlling the first drive sense circuits Sensing at least some of the mutual capacitances by the first plurality of traces, the method comprising: (a) driving the first plurality of traces via the first drive sensing circuits; (b) via the Two plurality of traces and the second drive sensing circuits sense the mutual capacitance; (c) driving the second plurality of traces via the second drive sensing circuits; (d) via the first plurality The traces and the first drive sensing circuits sense the mutual capacitance; and (e) detecting one or more of the touch screens based on the sensed mutual capacitance exceeding a predetermined voltage threshold The location of the touch. The method of claim 27, further comprising driving the first plurality of traces substantially simultaneously via the first drive sensing circuits or the second drive sensing circuits. The method of claim 27, further comprising driving the second plurality of traces substantially simultaneously via the first drive sensing circuits or the second drive sensing circuits. The method of claim 27, further comprising sensing at least some of the mutual capacitances substantially simultaneously via the first drive sensing circuits. The method of claim 27, further comprising sensing at least some of the mutual capacitances substantially simultaneously via the second drive sensing circuits. The method of claim 27, wherein sensing comprises detecting a voltage associated with the mutual capacitance. The method of claim 27, further comprising detecting the plurality of simultaneous or near simultaneous touches on the touch screen, wherein the detecting is associated with the mutual capacitance corresponding to the positions This comparator of voltage is implemented. The method of claim 27, further comprising driving the plurality of selected ones of the first drive sensing circuits and the second drive sensing circuits based on the detected positions of the touches. The method of claim 27, further comprising controlling the sensing of the plurality of selected ones of the first driving sensing circuits and the second driving sensing circuits based on the detected positions of the touches. The method of claim 27, further comprising generating a tag associated with the locations of the detected touches. The method of claim 27, further comprising generating a tag associated with the magnitude of the detected touch.